Rotary actuator



April 9, 1968 C. R. OLSEN 3,376,783

7 ROTARY ACTUATOB Filed April l1, 1966 @z E@ 4f United States Patent O 3,376,783 ROTARY ACTUATOR Charles R. Olsen, Los Angeles, Calif. (5409 Cromer Place, Woodland Hill, Calif. 91364) Filed Apr. 11, 1966, Ser. No. 541,729 Claims. (Cl. 89-1) ABSTRACT OF THE DISCLOSURE A rst pair of hollow tubes including an ignition charge are disposed in a spaced, end-to-end relation to a similar pair of tubes also including an ignition charge, the latter being in communication with a primary charge to be detonated. A rotatable disc is disposed in the space between the two sets of tubes and includes a pair of openings iilled with an ignition charge. The disc and tubes are included within a cylindrical housing. A hollow tubular member of non-circular cross-section includes internal longitudinally extending passageways of a generally helical configuration. One end of the tubular member is ailixed to the rotatable disc and the other end is aixed to a second disc secured within the cylinder. A squib mounted on the second disc is in communication with the interior of the tubular member and ignition of the squib reorients the tubular member by rotating the rst disc to align the ignition charge iilled openings with the ends of the tubes. Simultaneously upon reorienting of the rst disc electrical contacts carried by this disc and the cylinder are brought into contact ign-iting the ignition charge within the lirst set of tubes that is propagated along the tubes to detonate the primary charge.

This invention relates to means for producing rotary motion, and more particularly to apparatus for turning a device to be controlled.

The device of thel present invention has a relatively large scope of application. The invention therefore should not be limited to the specific uses disclosed herein. The invention has been found to possess exceptional utility as an explosive actuator. However, the invention will operate satisfactorily by the use of any uid under pressure. The uid under pressure may be supplied either by an explosive charge or squid or by any suitable means other than an explosive charge. For example, a hydraulic source may be employed. Further, a high pressure gas from a rocket motor or pressure vessel may also be employed.

In the past, rotary explosive actuators have incorporated elongated accordion type tubes or bellows formed in an arc. These actuators have several serious disadvantages. One is that extremely high friction is encountered in their operation. They also give a relatively small amount of rotation and always less than 360 degrees. They are large, heavy, complicated, and unreliable. They are also bulky.

In accordance with the device of the present invention, the above-described and other disadvantages of the prior art .are overcome by providing an elongated, twisted tube or the like having a non-circular cross section. One end of the tube is then closed and fixed to a device fto be rotated. A uid under pressure is then introduced to the interior of the tube to cause it to untwist. The action of the tube in untwisting thus produces the desired rotation of the device to be actuated thereby.

The kind of tube employed with the present invention may be -similar to that known as a twisted Bourdon tube. However, .a twisted Bourdon tube is always operated Within its elastic limit simply to give an indication of pressure. It has never been operated beyond its elastic limit to cause a device to be controlled to rotate. Note will be taken that Mice the explosive actuator of the present invention is employed to rotate a device. Moreover, the twisted tube of the present invention is untwisted beyond its elastic limit to give a permanent set to the rotation of the device to be controlled.

It is one advantage of the present invention that an effective friction-free explosive actuator may be constructed to produce a rotary displacement in a device to be controlled. The twisted tube of the invention is thus .an unusually eflicient rotary explosive actuator. The tube can also be suiciently long and twisted to produce a rotation of almost any angle either greater or less than 360 degrees. The actuator of the present invention is also small, light, uncomplicated and reliable. The twisted tube is long and slender. It therefore may be mounted in a compact position in a space vehicle where many explosive actuators are ordinarily required.

The above-described and other advantages of the present invention will be better understood from the following description `when considered in connection with the accompanying drawings.

In the drawings which .are to be regarded as merely illustrative:

FIG. l is a longitudinal view partly in section of one embodiment of the present invention;

FIG. 2 is a transverse view partly in section taken on the line 2-2 of the embodiment shown in FIG. 1;

FIG. 3 is a transverse sectional view similar tto FIG. 2 showing the position of the device after it has been actuated; and

FIGS. 4a, 4b, 4c, 4d, 4e, 4f and 4g are transverse sectional views of alternative twisted tubes which may be employed in accordance with the present invention.

In FIG. l, an explosive actuator of the present invention is indicated at 10. Actuator 10 is an arming device. Actuator 10 is employed in a space vehicle or the like to arm .a rocket motor, separation device or warhead. The device is ignited through the use of two cylindrical tubes 11 and 12. Tubes 11 and 12 contain explosive charges at 13 and 14. The left ends of tubes 11 and 12 are connected to conventional explosive or detonating means` A pair of tubes 15 and 16 corresponding to tubes 11 and 12 are also provided. Tubes 15 and 16 carry explosive charges at 17 and 18, respectively. The right ends of ftubes 15 and 16, as viewed in FIGURE 1, are connected to a rocket motor or other device to activate the rocket motor. The mounting and connection of Itubes 15 and 16 to the rocket motor is conventional.

As shown in FIG. 1, tubes 11 and 12 are separated from tubes 15 and 16 by a disc 19. Disc 19 is solid except for an opening at Z0, a slot at 21 shown in FIGS. 2 and 3, and two cylindrical holes 22 and 23.

When the rocket motor is disarmed, solid portions of disc 19 cover the ends of tubes 11 and 12 as shown in FIG. 2. This efectively separates explosive charge 13 from explosive charge 17. It also separates explosive charge 14 from explosive charge 18. This means that when the device 10 is disarmed, should explosive charges 13 or 14 be ignited, explosive charges 17 Aand 18 will not be ignited and the rocket motor or device will therefore not be ignited.

The manner in which the rocket motor or device is ignited through explosive charges 17 and 18 is as follows. Disc 19 is turned 90 degrees from the position shown in FIG. 2. Note will be taken that the disc 19 shown in FIG. 3, has, in fact, been turned degrees from the position shown in FIG. 2. As stated previously, disc 19 has holes 22 and 23 therethrough. Holes 22 and 23 are lled with explosive charges 24 and 25 to provide explosive leads. Thus, when disc 19 is turned 90 degrees in the direction of an arrow 26 shown in FIG. 3, explosive charges 13, 25 and 17 become aligned. Similarly, explosive charges 14, 24 and 18 become aligned. The device 10 is then armed. That is, when charge 13 is ignited, charge 25 is ignited immediately thereafter. Similarly, charge 17 is ignited immediately after charge 25 is ignited. The ignition of charge 14 will also cause the ignition of charge 24. The ignition of charge 24 will, in turn, cause the ignition of charge 1S.

Thus far in this detailed description, the structures described are conventional. The present invention relates to a device for turning disc 19 approximately ninety degrees.

Note will be taken in FIGS. l, 2 and 3 that the structure thus far described is supported in a cylindrical housing 27. A pin 28 is fixed in housing 27. Pin 2-8 is slidable in disc slot 21. Pin 28 therefore limits rotation of disc 19 to 90 degrees.

The device of the present invention includes a twisted tube 29. The right end of tube 29 is closed in disc recess 20 at 30. The seal provided by the tube end 30 is fluid tight. As shown in FIGS. 2 and 3, tube 29 has a cross section which is approximately in the shape of a dumbbell.

Tubes 11 and 12 are supported in a disc spacer 31 inside housing 27. Disc 31 carries the left end of tube 29 in a conventional way. That is, disc 31 carries the left end of tube 29 in a manner identical to the manner in which a linear explosive actuator is carried. This is to distinguish the conventional linear actuator from the rotary actuator of the present invention.

A squib 32 is fixed inside the left end of tube 29 in the same manner as a squib is conventionally fixed inside one end of a linear explosive actuator of the prior art. Thus, to this extent, squib 32 is fixed inside tube 29 in a conventional way. Squib 32 itself is conventional. Squib 32 has a pair of electrical leads 33 and 34 to detonate it. The explosive charge of squib 32 is indicated at 35. Conventional means may be connected to leads 33 and 34 to detonate charge 35 of squib 32.

The rotary explosive actuator of the present invention operates as follows. As long as disc 19 remains in the position shown in FIG. 2, disc 19, which is non-combustible, separates explosive charges 13 and 14 from explosive charges 17 and 18. This means that device 10 is disarmed in that detonation of charges 13 and 14 will not cause detonation of charges 17 and 18.

When it is desired to arm the device 10, the charge 35 of squib 32 is detonated. Note will be taken that in this case, spacer 31 is fixed to housing 27. Similarly, tube 29 is fixed to spacer 31 at 36. As stated previously, squib 32 is fixed inside of tube 29. The explosive charge 3S of squib 32 is then detonated and the explosion inside tube 29 causes tube 29 to untwist and rotate disc 19 to the position shown in FIG. 3. The device 10 is then armed.

Alternative cross sectional shapes for tube 29 may be used, if desired. For example, tube 37 having a generally cross sectional shape of an ellipse or oval may be employed as shown in FIG. 4a. Simply a attened tube of conventional Bourdon tube shape as indicated at 38 in FIG. 4b may be employed. A cross-shaped tube 39 may be employed as shown in FIG. 4c. A Y-shaped tube 40 -may be employed as shown in FIG. 4d. A diamond-shaped tube may be employed as indicated at 41 in FIG. 4e. A clover leaf tube 42 may be employed as shown in FIG. 4f. A polygon shaped tube 43 may be employed as shown in FIG. 4g.

In accordance with the device of the present invention, tube 29 is untwisted beyond its elastic limit so that disc 19 will remain in the position shown in FIG. 3 after the charge 3S of squib 32 has been detonated.

Note will be taken that switch contacts 44 and 4S are spaced apart as in FIG. 2 and contact each other as shown in FIG. 3.

The switch on disc 19 may be a part of or independent of an arming device.

From the earlier description of the prior art rotary actuators, it will be understood that the prior art rotary actuators actually involve the use of a linear explosive actuator in a rotory application. As stated previously, this prior art device encountered considerable friction. Note will be taken that disc 19 rotates in a relatively friction free environment. The explosive actuator 10 of the present invention therefore operates very effectively. Tube 29 may be sufficiently long and twisted a sufiicient number of turns to produce a rotation of disc 19 or any other device of almost any angle either greater or less than 360. Note will be taken that the actuator of the present invention is also small, light and uncomplicated, yet reliable. The twisted tube 29 is long and slender. It therefore may be mounted in a compact position in a space vehicle where many explosive actuators are ordinarily required.

The Word fluid is normally defined to include either a liquid or a gas. Thus, for use in this specification and claims, the word uid is hereby specifically defined to include but not be limited to a liquid or a hot or cold gas.

Although only a few embodiments of the present invention have been described and illustrated herein, many changes and modifications thereof will of course suggest themselves to those skilled in the art. The present invention should therefore not be limited to the embodiments selected for this disclosure, the true scope of the invention being defined only in the appended claims.

What is claimed is:

1. An explosive actuator device comprising:

base member means;

first and second hollow tubular member means arranged in paired end-to-end spaced relation, said member means including an ignitable charge therewithin;

a rotatable body disposed between the opposed ends of the tubular members, said body including porting lead means that on rotation of the body is rbrought into registry with the opposed ends of the tubular member means;

an elongated pre-twisted Bourdon type tubular element having one end closedly afiixed to the rotatable body and the other end anchored to said `base member means, said tubular element extending generally lengthwise of the element and defining a substantially helical path, which element is so configured and constrained as to provide rotary motion upon pressurization thereof; and

a fluid pressure generating device communicating with the anchored end of said element whereby upon actuation of said device pressurized fiuid is provided interiorly of the element to effect untwisting of the element and rotation of the body to align the lead means in the rotatable body with the spaced tubular member ends.

2. An explosive actuator as in claim 1, comprising electrical circuit switch means having contact means carried by the rotatable body which upon rotation thereof co-act with complimentary switch contact means mounted adjacent the `body for electrically igniting the charge carried within one of the tubes which in turn ignites the charge in the other tube via the porting lead carried within the body.

3. The invention as defined in claim 1, wherein the cross section of said element is approximately the shape of an oval.

4. The invention as defined in claim 1, wherein the cross section of said element is approximately the shape of an ellipse.

5. The invention as defined in claim 1, wherein the cross section of said element is approximately the shape of a cross.

6. The invention as defined in claim l, wherein the cross section of said element is approximately the shape of a Y.

6 7. The invention as defined in claim 1, wherein the References Cited glossdeectiotii of said element is approximately the shape UNITED STATES PATENTS a lamon 8. The invention as defined in clim 1, wherein the ggg-27; l; Rockwell --Zf Cross section of said element is approximately the Shape 0f 5 21 f 4 VOSS a clover leaf. 3,110,302 1/1964 Barr 89-L01 9. The invention as defined in claim 1, wherein the 3,188,420 6/1965 HUSOH 200-81-8 t f 'd 1 t t i ih h giosdblgf Sal e amen 1S approxlma e y e s ape BENJAMIN A. BORCHELT, Primmy Examiner.

10. The invention as dened in claim 1, wherein the 10 SAMUEL W ENGLE Emmi-nen cross section of said element is approximately the shape of a polygon. T. H. WEBB, Assistant Examiner. 

